Valid 191200Z – 201200Z
…THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE FLORIDA
PENINSULA TO COASTAL CAROLINAS…
Isolated damaging winds, and perhaps a few tornadoes, can be
expected from the central Florida Peninsula to the Carolina Coast.
Well-defined mid-level short-wave trough has progressed into the
eastern Gulf of Mexico where it appears to be influencing the
northeastward-moving Tropical Storm Nestor. This negative-tilted
short wave is forecast to eject into SC by 20/00z, then NC by the
end of the period. Latest model/NHC guidance suggests Nestor will
track inland across the FL Panhandle into southwest GA by early
afternoon. As this occurs, 70F surface dew points will surge north
ahead of the surface low. While lapse rates will necessarily be weak
with this tropical system, lower 70s surface dew points should prove
adequate for buoyancy supporting sustained rotating updrafts.
Additionally, wind profiles will increase markedly ahead of the low
and the greatest tornado threat would preferentially favor
supercells that develop along the northward-advancing warm front.
Early this morning, strongest band of deep convection producing
lightning was located about 40mi west of the Peninsula. Leading edge
of this activity is expected to progress inland over the next few
hours with an attendant tornado threat. Broken bands of
strong/severe convection should surge across the peninsula primarily
before 18z then the focus for severe should orient itself along the
warm front from southern GA to coastal NC late. Primary tornado
threat should be limited to area where surface dew points can rise
into the lower 70s, and the northern extent of this moisture should
be limited to near-coastal regions.